ON THE BIOLOGY OF GONATOPUS PILOSUS Thoms--Professor Josef Mik, in theSeptember number of the _Wiener Entomologische Zeitung_ (pp. 215-221,pl. iii), gives a most interesting account of the life history of thecurious Proctotrupid, _Gonatopus pilosus_ Thoms., which has not beforebeen thoroughly understood. Ferris, in his "Nouvelles excursions dansles grandes Landes," tells how, from cocoons of parasitic larvae on_Athysanus maritima_ (a Cicadellid) he bred _Gonatopus pedestris_, butthis he considered a secondary parasite, from the fact that it issuedfrom an inner cocoon. It appears from the observations of Mik, however,that it was in all probability a primary parasite, as with the speciesstudied by the latter (_G. pilosus_) the larva spins both an outerand an inner cocoon. The larva of _Gonatopus pilosus_ is an externalparasite upon the Cicadellid _Deltocephalus xanthoneurus_ Fieb. The eggsare laid in June or July, and the larvae, attaching themselves at thejunction of two abdominal segments, feed upon the juices of their host.But one parasite is found upon a single Cicadellid, and it occasionallyshifts its position from one part of the abdomen to another. Leaving itshost in September, it spins a delicate double cocoon in which it remainsall winter in the larva state, transforming to pupa in May, and issuingas an imago in June.

It will be remembered that the female in the genus Gonatopus isfurnished with a very remarkable modification of the claws of the fronttarsi, which are very strongly developed, and differ somewhat in shapein the different species. It has usually been supposed that these clawswere for the purpose of grasping prey, but Professor Mik offers the moresatisfactory explanation that they are for the purpose of grasping theCicadellids, and holding them during the act of oviposition.

It is interesting to note that there is in the collection of theDepartment of Agriculture a specimen of _Amphiscepa bivittata_ Say,which bears, in the position described above, a parasitic larva similarto that described by Mik. It left its victim and spun a white cocoon,but we failed to rear the imago. It is probably the larva of aGonatopus, and possibly that of the only described American species ofthe genus, _Gonatopus contortulus_ Patton (_Can. Ent._, xi p. 64).

* * * * *

SPECIES OF OTIORHYNCHIDAE INJURIOUS TO CULTIVATED PLANTS--Of ournumerous species of this family, we know the development and earlierstages of only one species, viz, Fuller's rosebeetle (_AramigusFulleri_[1]). A few other species have attracted attention by the injurycaused by them as perfect insects. They are as follows: _Epicoerusimbricatus_, a very general feeder; _Pachnoeus opalus_ and _Artipusfloridanus_, both injurious to the orange tree. Of a few other specieswe know the food-plants: thus _Neoptochus adspersus_ feeds on oak;_Pachnoeus distans_ on oak and pine; _Brachystylus acutus_ is onlyfound on persimmon; _Aphrastus toeniatus_ lives on pawpaw (but notexclusively); _Eudiagogus pulcher_ and _rosenschoeldi_ defoliate thecoffee-weeds (_Cassia occidentalis_ and other species of the samegenus). Two very common species, _Pandeleteius hilaris_ and _Tanymecusconfertus_, appear to be polyphagous, without preference for anyparticular plant. Very recently the habits of another species, _Anametisgrisea_ Horn, were brought to our knowledge by Mr. George P. Peffer, ofPewaukee, Wis., who sent us specimens of the beetle accompanied by thefollowing communication: "The larger curculio I send you is workingaround the roots of apple and pear trees, near the surface of the groundor around the union where grafts are set. I found fifteen of the larvaeon a small tree one and a half inches in diameter. The beetle seems tolay its eggs just where the bark commences to be soft, near or partlyunder the ground. The larvae eat the bark only, but they are so numerousas to girdle the tree entirely in a short time."--_C. V. Riley_.

BOMBYLIID LARVAE DESTROYING LOCUST EGGS IN ASIA MINOR.--The eggs oflocusts in Cyprus and the Dardanelles, as we learn from the Proceedingsof the London Entomological Society, are much infested with theparasitic larvae of _Bombyltidae_, though these were previously notknown to occur on the island. This fact shows that the habit which wediscovered among some of our N. A. _Bombyliids_ recurs in other partsof the world, and we have little doubt that careful search among locusteggs will also reveal the larval habits of some of the _Meloidae_ inEurope and elsewhere. Indeed, notwithstanding the closest experimentsof Jules Lichtenstein, which show that the larva of the Spanishblister-beetle of commerce will feed on honey, we imagine that its morenatural food will be found in future to be locust eggs. The particular_Bombyliid_ observed by Mr. Frank Calvert destroying locusts in theDardanelles is _Callostoma fascipennis_ Macq., and its larva and pupavery closely resemble those of _Triodites mus_. which we have studiedand figured (see Vol. XV., pl. vi.). We quote some of Mr. Calvert'sobservations:

"On the 24th of April I examined the larvae in the ground; the onlychange was a semi-transparent appearance which allowed of a movableblack spot to be seen in the body. On the 8th June about fifty per cent.of the larvae had cast a skin and assumed the pupal state in theirlittle cells: the color yellowish-brown, darkening to gray in the moreadvanced insect. About one per cent. of the cells, in which were twoskins and an aperture to the surface, showed the perfect insect to havealready come out of them. A gray pupa I was holding in my hand suddenlyburst its envelope, and in halt a minute on its legs stood a fly, thusidentifying the perfect insect.... I found the fly, now identified,sucking the nectar of flowers, especially of the pink scabious andthistle, plants common in the Troad. (Later on I counted as many assixteen flies on a thistle-head.) The number of flies rapidly increaseddaily until the 13th, when the ground appeared pitted all over withsmall holes from whence the parasite had issued. A few pupae were thenstill to be found--a larva the rare exception. The pupal state thusseems to be of short duration. It was very interesting to watch theflies appearing above ground; first the head was pushed out; then, withrepeated efforts, the body followed; the whole operation was over intwo or three minutes; the wings were expanded, but the colors did notbrighten until some time after. Occasionally a pupa could not castoff its envelope, and came wriggling out of the ground, when it wasimmediately captured by ants. Unfortunate flies that could not detachthe covering membrane adhering to the abdomen, also fell a prey, asindeed many of the flies that could not get on their legs in time. Theflies for the first time 13th June, were seen to pair, but this rarely."

* * * * *

SPARROWS IN THE UNITED STATES.--EFFECT OF ACCLIMATION, ETC.

The house sparrows were first brought to New York city in 1862. Theymight have been introduced in consideration of the scientific usefulnessof the experiment; but the importation was made solely in view of thebenefit to result from their immense consumption of larvae.

I have long observed peculiarities in their acclimation which are hardlyknown at all, and which must have a scientific importance. The subjectmight also be worthy of general interest, so numerous and familiar havethe sparrows become all over our country.

Walking on Fifth avenue, or in the parks of the city, during thebreeding season, one's attention is repeatedly attracted by the pitifulshrill call of a sparrow fallen on the pavement upon its first attemptat flight, or by the stronger note of a mother sparrow, sharplybewailing the fate of a little one, killed by the fall, or dispatchedalive by the cat.

Should we take and examine these little weaklings, we should findgenerally that they are at a period when they normally should have thestrength for flight, and we should also find that they are almost alwaysof a lightish tint, some with head white, others with streaks and spotsof white on the tail or back, and occasionally one is found entirelywhite, with red eyes--a complete albino. It is an accepted fact that thecity-sparrow is everywhere of a lighter color than that of the country.But here the greater lightness exists in so many cases, to sucha degree, and particularly in female sparrows, that it should bediscussed, at least in part, under the head of albinism.

That so many which lack the muscular strength in their wings should beso generally affected with albinism, is a significant fact to thoseinterested in this phenomenon.

Many hold, with Darwin, that this extraordinary want of coloring matter,occasionally met with in all animals, is not to be regarded as an indexdenoting an unhealthful condition of the animal. That it is so oftenunited in the young sparrow with physical inability, argues favorablyfor those who bold a different view.

In my observations, what has struck me as a most curious fact, and whatI have found to be generally ignored, is that this wide-spread albinismand general weakness of our acclimated house-sparrow are not found amongits progenitors.

Throughout several sojourns that I made in Europe. I searched for atoken of the remarkable characteristics existing here, but I neversucceeded in finding one in England, France, or in Germany, nor have Imet an observer that has.

This albinism and weakness, existing simultaneously to such an extent inour young house-sparrows, are evidently the result of their acclimation.

The hypothesis that our now _numerous_ sparrows, being descended froma _few_ European birds, and that, probably, continual and closereproduction among individuals of the same stock, as in the case of ouroriginal _few_ sparrows, has encouraged weakness in the race, can hardlyserve as an explanation of this phenomenon, because the sparrow is soprolific that, after a few years, so many families had been formed thatthe relation between them became very distant.

The reason for the greater proportion of albinism found in the young isobvious; the young sparrows affected with albinism, lacking usually thephysical strength to battle their way in life, meet death prematurely,and thus a very small proportion of the number is permitted to reachmaturity, while those that do owe it to some favoring circumstance. Manyare picked up and cared for by the public; and among those to whom thesesparrows generally owe such prolongation of life are the policemen inour public parks, who often bring these little waifs to their homes,keeping some, and sending others out into the world, after caring forthem until they have acquired the sufficient strength. However, almostall of these albino-sparrows are picked up by the cat, and immediatelydisposed of to the feline's physical benefit. They form such a prominentdiet among the cats near Washington Park, where I live, that, upon theremoval of some of our neighbors to the upper part of the city, it wasnoticed that their cat became dissatisfied and lean, as sparrow-meat isnot to be found so extensively there, but it finally became resigned,finding it possible to procure about three sparrows daily.

And here attention should be called to the method employed by our catsto catch not only the weak, but fine, healthy sparrows as well; it oughtperhaps to be looked upon as a mark of intellectual improvement, fororiginally their attempts consisted chiefly in a very unsuccessfulgiving chase to the flying bird, whereas the cats of to-day are skilledin a hundred adroit devices. It has often been a source of enjoyment towatch their well-laid schemes and delicate maneuverings.

What wonder then, with such dainty fare at his disposal, that the cat isoften found to have become indifferent to rats, and even to mice?

There are several notable changes, no more desirable than the foregoing,which have been caused by the introduction of the house-sparrow. Theonly positive benefit which occurs to me is that the measuring worm,which formerly infested all our vegetation, is now very nearly extinctthrough the instrumentality of the sparrows. A pair of these, during thebreeding-season, destroys four thousand larvae weekly.

In some places, complaints are made that their untidy nests mar theappearance of trees and walls.

The amount of havoc in our wheatfields created yearly by them isenormous. Their forwardness and activity have driven all other birdsfrom where they have settled, so that the hairy caterpillars, whichsparrows do not eat and which used to be extensively consumed by otherbirds, are now greatly on the increase, probably the only creatures, atpresent, enjoying the domestication of the sparrow in this country....I have also to remark that the sparrows here betray much less pugnacitythan in Europe.--E.M., M.D.

* * * * *

It is stated in the _Chemical Review_ that recent analyses of the waterfrom the _Holy Well_ at Mecca, which is so eagerly drunk by pilgrims,show this water to be sewage, about ten times stronger than averageLondon sewage.

* * * * *

HOW TO ESTABLISH A TRUE MERIDIAN.

In looking over the excellent article of Professor S. M. Haupt, in theSCIENTIFIC AMERICAN SUPPLEMENT, No. 360, on the subject of finding themeridian, I discovered that one important step is not given, which,might prove an embarrassment to a new beginner.

In the fourth paragraph, in the third column of page 5,748, he says:"Having now found the altitude, correct it for refraction, ... and theresult will be the latitude."

It will be observed that this result is only the true altitude of thestar. The _latitude_ is found by further increasing or diminishing thisaltitude by the polar distance of the star.

This paper will be of great value to engineers and surveyors, for theelementary works on surveying have not treated the subject clearly.

H. C. PEARSONS, C.E.

Ferrysburg, Mich.

* * * * *

A catalogue, containing brief notices of many important scientificpapers heretofore published in the SUPPLEMENT, may be had gratis at thisoffice.

* * * * *

THE SCIENTIFIC AMERICAN SUPPLEMENT.

PUBLISHED WEEKLY.

TERMS OF SUBSCRIPTION, $5 A YEAR.

Sent by mail, postage prepaid, to subscribers in any part of the UnitedStates or Canada. Six dollars a year, sent, prepaid, to any foreigncountry.

All the back numbers of THE SUPPLEMENT, from the commencement, January1, 1876, can be had. Price, 10 cents each.

All the back volumes of THE SUPPLEMENT can likewise be supplied. Twovolumes are issued yearly. Price of each volume, $2.50, stitched inpaper, or $3.50, bound in stiff covers.

COMBINED RATES--One copy of SCIENTIFIC AMERICAN and one copy ofSCIENTIFIC AMERICAN SUPPLEMENT, one year, postpaid, $7.00.

A liberal discount to booksellers, news agents, and canvassers.

MUNN & CO., PUBLISHERS,

261 BROADWAY, NEW YORK, N. Y.

* * * * *

PATENTS.

In connection with the SCIENTIFIC AMERICAN, Messrs. MUNN & Co. areSolicitors of American and Foreign Patents, have had 35 years'experience, and now have the largest establishment in the world. Patentsare obtained on the best terms.

A special notice is made in the SCIENTIFIC AMERICAN of all Inventionspatented through this Agency, with the name and residence of thePatentee. By the immense circulation thus given, public attention isdirected to the merits of the new patent, and sales or introductionoften easily effected.

Any person who has made a new discovery or invention can ascertain, freeof charge, whether a patent can probably be obtained, by writing to MUNN& Co.

We also send free our Hand Book about the Patent Laws, Patents, Caveats.Trade Marks, their costs, and how procured, with hints for procuringadvances on inventions. Address